US 5,385,053 A · Fiber optic pressure sensor systems

Abstract

The invention is related to numerous improvements for fiber optic measuring systems, and principally those utilizing a deformable diaphragm for sensing pressure. One feature of the invention is particularly oriented to automotive engine combustion chamber pressure measurement. For that application, a sensing tip shielding technique is described using a sintered metal porous plug, which reduces temperature fluctuations experienced at the sensing tip and shields the sensing tip from corrosive materials. A technique for compensation of a fiber optic pressure sensor is also described. In that method, a referencing wavelength is partly reflected and partly transmitted past a filter coating at the sensing end of the optical filament. This technique of the sensor provides improved calibration.

Claims10

Dependent claims

A fiber optic pressure sensor system comprising:

an optical fiber having a sensing tip at a first end with a pressure sensitive element, said pressure sensitive element modulating a pressure sensing light signal injected into the opposite second end of said optical fiber,
optical means for generating said pressure sensing light signal and a reference light signal, said light signals having different wavelengths,
filter means at said fiber first end for allowing transmission of said pressure sensing light signal and reflecting a portion of the energy of said reference light signal allowing a transmitted portion of said reference light signal to be modulated by said pressure sensitive element, and
signal processing means for generating an output related to pressure at said sensing tip and where the amplitude of both returned reference and pressure sensing light signals are used to generate an output related to pressure at said sensing tip.

1 more element

Dependencies are inferred from the claim text.

Fiber optic pressure sensor systems

Life of this patent

Fiber optic pressure sensor systems

Life of this patent

Abstract

Claims10